The proposed research is concerned with classification issues related to the outpatient neurotic conditions of anxiety and depression. Its objective is to examine existing classification systems (typologies; syndromes) through systematic follow-up over a two year period of symptomatic volunteers selected for patterns of symptomatology similar to actual anxious or depressed outpatient neurotics and for a history of no prior treatment. To be examined are clinician-derived typologies, the Research Diagnostic Criteria (RDC) of Spitzer, Endicott, and Robins and the classification system proposed by Klein, and psychometrically derived syndromes based on the Hopkins Symptom Checklist (HSCL) and on the Profile of Mood States (POMS). The major goals of the study are to describe and document the natural history of untreated neurotic conditions and to validate existing classification systems with outcome as a criterion.